I have my monitor currently connected to my PC using an HDMI cable. I have been getting flickering screens. They only last a few seconds. Today it happened again. I got this message for the first time.

Dell 27 Monitor
The current input timing is not supported by this display. Please change your input timing to 3840x2160, 60Hz or any other monitor listed timing as per the monitor specifications
After that message, I went into the display adapter settings and changed the refresh rate to 60. So far I haven't gotten any other messages like that but the flickering is still happening. When the monitor flickers during the few seconds it happens, the power light indicator on the monitor is solid white. The screen goes black.

I have no idea what it could be or if my PC is supported by this monitor. I haven't tried it on another PC yet. Any suggestions to try are much appreciated.

Dell 27 4K USB-C Monitor - S2722QC

System specs

Dell XPS 8900
Processor: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz 4.01 GHz
Installed RAM: 16.0 GB
System type: 64-bit operating system, x64-based processor
Display adapter: Nividia GeForce GTX 970
OS: Windows 10 Home 22H2